Electric parking brake systems have been provided in vehicles to allow the application and release of the parking brake via electrical signal, eliminating the current mechanical connection, i.e. cable and lever. These systems typically include an electro-mechanical actuator connected to the brake caliper either by a cable, as in the drum in head, or directly attached to the brake caliper. The actuator converts electrical power to rotational mechanical output power for moving the cable or drive screw and applying the brakes.
In addition, audible noise is a significant feature differentiating actuators in parking brake systems and many other actuation applications. In some applications, a loud system is desirable to alert an operator that the actuator is being cycled. In other applications, a quiet system is desirable to keep in-cabin noise to a minimum.
There is therefore a need for an efficient, reliable and cost-effective actuator design for a vehicle parking brake system that overcomes the deficiencies of the prior art. There is a further need for a method of tuning the actuator for audible noise performance.